The present invention relates to a honeycomb structure, more specifically, to a honeycomb structure capable of inhibiting a honeycomb segment from being detached from a bonding member when combustion of trapped particulate matter (regeneration) is repeated and capable of inhibiting the honeycomb structure to be separated.
A ceramic honeycomb structure excellent in thermal resistance and corrosion resistance is employed as a carrier for a catalytic device or a filter used for an environmental measure, collection of a specific material or the like in various fields such as chemistry, electric power, and iron and steel. In particular, recently, a honeycomb structure plugged alternately in cell open portions on both the end faces as a plugged honeycomb structure is frequently used as a diesel particulate filter (DPF) for trapping particulate matter (PM) discharged from a diesel engine or the like. As a material for the honeycomb structure used in a high temperature corrosive gas atmosphere, silicon carbide (SiC), cordierite, aluminum titanate (AT), and the like, which are excellent in thermal resistance and chemical stability, are suitably used.
Since silicon carbide has relatively large thermal expansion coefficient, a honeycomb structure formed by the use of silicon carbide as the framework may cause a defect due to thermal shock upon use if the size is large. In addition, a defect may be caused due to thermal shock upon combusting and removing trapped particulate matter. Therefore, in the case of manufacturing a honeycomb structure using silicon carbide as the framework and having a predetermined or larger size, generally, a plurality of small plugged honeycomb structured segments are manufactured, and then they are bonded together to obtain one large bonded article. The outer periphery of the bonded article is subjected to coarse machining and grinding to obtain a plugged honeycomb structure having a desired shape such as a cylindrical shape (see, e.g., JP-A-2003-291054). The bonding of the segments is performed by the use of a bonding material, which is applied on a side face (outer peripheral wall) of a predetermined segment, and a plurality of segments are bonded together at the side faces to obtain a honeycomb structure where a plurality of segments are bonded by means of the bonding member (see, e.g., JP-A-2003-117322).
Such a honeycomb structure formed by bonding honeycomb segments with a bonding material (bonding member) at side faces thereof has a problem of detachment of a honeycomb segment from the bonding member due to repeated heating and cooling when combustion of trapped particulate matter (regeneration) is repeated to sometimes cause separation of the honeycomb structure.